Visceral fat appears to be the most worrying because it is associated with greater deterioration of the brain’s white matter.
One published last year in the journal Nature Mental Health suggests that location of fat storage in the body can play a crucial role in brain health and cognitive aging, regardless of a person’s total weight.
Research has found that different types of body fat are linked to distinct changes in brain structure, brain function and cognitive performance in middle-aged and older adults.
The study was led by Anqi Qiu of Hong Kong Polytechnic University and analyzed data from more than 18,000 participants from the UK Biobank. Participants, with an average age of about 62, underwent detailed body composition exams, various forms of brain imaging, and a series of cognitive tests measuring memory, reasoning, processing speed, and executive function.
Researchers examined the fat stored in arms, legs, trunk and deep abdominal regionknown as visceral fat. Advanced statistical techniques allowed the team to isolate the effects of each fat deposit regardless of total body weight.
The results revealed that fat distribution is strongly associated with specific patterns of brain changes. Higher levels of fat in the arms and trunk have been associated with thinning of the sensorimotor cortexa region involved in movement and touch. Increased fat in the arms has also been associated with reduced hippocampal volumea brain structure crucial to memory.
All forms of body fat examined were associated with a reduction in the size of several brain regions depths and less communication between areas involved in movement and coordination.
Not so much, visceral fat emerged as the most worrying. The study found that fat around internal organs was most strongly associated with the deterioration of white matter — the network of nerve fibers that allows communication between different parts of the brain. The researchers observed signs of reduced nerve fiber densitygreater fluid accumulation and structural disorganization in these neural pathways.
The analysis also suggested that excess fat may accelerate the brain’s biological aging process. Using computational models to estimate “brain age,” researchers found that accelerated aging in neural networks linked to movement, memory and autonomous thought appears to mediate declines in cognitive performance. Visceral fat consistently presented the stronger negative relationship with thinking and memory capabilities.
Despite the findings, the researchers cautioned that the study does not prove causality. Because we analyzed participants at a single point in time, it is not possible to determine whether fat accumulation causes brain changes or whether underlying brain processes contribute to fat distribution.
